Coherent tobacco strip and the process for preparing the same



United States Patent 3,379,198 COHERENT TOBACCO STRIP AND THE PROCESSFOR PREPARING THE SAME James D. Mold and Andrew G. Kallianos, Durham,N.C., assignors to Liggett 8: Myers Tobacco Co., New York, N.Y., acorporation of New Jersey No Drawing. Filed June 9, 1965, Ser. No.471,493

18 Claims. (Cl. 131140) This invention relates to improved coherenttobacco strip for incorporation in smoking tobacco articles. Moreparticularly, this invention relates to the treatment of the componentsof coherent tobacco strip for the purpose of increasing the strength ofthe sheet and/or effecting a reduction in the irritation factorsinvolved in the smoking of tobacco articles containing this product.

Coherent tobacco strip hereinafter called (CTS) is typically composed oftobacco fines, ground stems or other fibrous materials, and humectantswhich are bound with an adhesive material into a continuous sheet whichcan then be cut and blended with natural leaf tobaccos for themanufacture of cigarettes. Processes for the preparation of CTS aredisclosed in US. Patents 2,708,175 issued May 10, 1955; 2,845,933 issuedAug. 5, 1958; and Re. 24,424 issued Feb. 4, 1958, all of which patentsare assigned to Liggett & Myers Tobacco Co.

Cigarettes manufactured solely from CTS possess smok ing qualities whichare judged undesirable both in terms of taste and irritation factorswhen compared to cigarettes manufactured from natural leaf tobacco. Suchirritation is primarily noted in the mouth, nose and throat. Theseundesirable characteristics of CTS limit the extent of its use incommercial cigarettes. Reduction of the irritation would produce a blandproduct which could then be incorporated into the cigarette blend assuch to produce a smoke of milder characteristics or which could beappropriately flavored prior to blending with the natural leaf tobacco.Moreover, the processing of CT S for incorporation into smoking tobaccoarticles involves considerable mechanical handling of these materialswith the resultant problem of fragmentation which is undesirable for theeconomic manufacture of cigarettes. Strenghtening of the CTS would helpreduce the fragmentation of the strip and thereby alleviate some of theproblems involved in handling these materials.

It is therefore an object of this invention to provide a process forimproving the smoking qualities of CTS by decreasing the irritationeffects in the smoke.

It is another object of this invention to provide a process forproducing CTS which has improved physical properties resulting in anincreased flexibility strength and tensile strength so that it willfragment less during the customary handling associated with themanufacture of smoking tobacco articles.

It is a further object of this invention to provide CTS compositionswhich have reduced irritation effects when said compositions areincorporated in smoking articles.

It is a still further object of this invention to provide CTScompositions of increased flexibility and tensile strengths.

These and other objects will be apparent from the detailed descriptionwhich follows.

In accordance with this invention, there is provided a process for thepreparation of an improved CTS which comprises thoroughly mixing aquantity of tobacco fines, ground stems or other fibrous materials, atleast one humectant, and an adhesive substance with a sufficientquantity of water, heating said mixture in a reactor under steampressures of up to 20 p.s.i.g. for a period of time up to 20 minutes attemperatures not exceeding 225 F. in the ground tobacco and recoveringthe treated CTS.

When the CTS components are subjected to this treatment and thenmanufactured into a sheet, the resultant product possesses improvedphysical properties resulting in increased flexibility strength andtensile strength and, upon smoking in the form of a suitable tobaccoarticle, produces a sensation judged to be more desirable in terms oftaste and lower irritation factors than is the case for CTS produced byconventional procedures. It is an essential feature of this inventionthat the adhesive substance be incorporated in the mixture ofingredients prior to the autoclaving treatment in order to realize thebenefits from increased flexibility strength and tensile strength,although this is not a necessary feature with regard to the benefits inreduced irritation of the smoke.

The humectants which may be employed in this invention are any of theconventional humectants such as glycerin, propylene glycol, etc. Guargum is the adhesive material which is preferred for use in the processesand compositions of this invention.

Broadly speaking, parts of the damp CTS compositions of this inventionwill comprise about 45 to 60 parts of tobacco fines and ground stems orother fibrous materials, preferably about 50 to 55 parts by weight;about 1 to 8 parts by weight of hurnectant, preferably about 2 to 5parts by weight, and about 1 to 10 parts by weight adhesive material,preferably about 2 to 8 parts by weight with the balance of saidcomposition being water.

In carrying out the process of this invention, the CTS ingredients arethoroughly mixed and placed in a suitable reactor such as an autoclavewhich is kept under steam pressure of from about 8 to about 20 poundsp.s.i., with the preferred pressure being about 16 p.s.i.g. The CTS isautoclaved for about 10 to 20 minutes and the temperature at the centerof the tobacco mass in the autoclave is controlled such that it ismaintained in the range of about to 225 F.

Generally in the manufacture of CTS, about 9 parts of water is used forevery 10 parts of tobacco fines employed in the mix. In carrying out theprocess of this invention, it may be desirable in some instances to useless than the normal amount of water in the mix in order to compensatefor the extra water which may condense in the mix during theautoclaving. The diminution in the amount of water charged to theautoclave is dependent on the nature of the vessel, time of treatment,temperature, pressure etc., as will be apparent to those skilled in theart from the detailed examples set forth below.

We have found that if the adhesive is added to the other CTS componentsprior to autoclaving the components, the CTS sheets have increasedflexibility strength and tensile strength, as well as improved smokingcharacteristics. If the adhesive is added either after the autoclavingstep or left out of the composition entirely, the CTS exhibits improvedsmoking characteristics, i.e., a reduction in the irritation in thesmoke, but does not possess the improved flexibility and tensilestrength.

It will be appreciated that the optimum conditions of treatment formaximum benefits in improved taste and reduced irritation of the smokeof the product are not necessarily coincidental with those resulting inmaximum sheet strength, Generally speaking, the maximum conditions oftreatment, i.e. higher temperatures, times, pressures, etc. maximize theincrease in the sheet strength but do not appreciably effect a reductionin irritation of the smoke. The minimum conditions of treatment, i.e.lower pressures, times, temperatures, etc. maximize the improvement inthe reduction in irritation of the smoke but do not appreciably improvethe sheet strength. The conditions of treatment are chosen with a viewto the specific composition desired keeping in mind the smokingcomposition into which the CTS is ultimately to be incorporated.

For a more detailed description of the invention, reference should nowbe had to the following examples.

Example 1 A sample consisting of 726 grams of powdered tobacco and stemmaterials, 83.2 grams of guar gum, 64 grams of alpha cellulose, 48 ml.of humectant glycols, and 350 ml. of water was prepared. All of thecomponents were mixed thoroughly. The resulting moist mix was placed ina 3-liter flask and treated in an autoclave for 20 minutes at a gaugereading 16 p.s.i. of steam pressure. It was determined that under theseconditions the maximum temperature attained at the center of the tobaccomass was 205 F and at the surface, 225 F. After cooling, the materialwas admixed with an additional 125 ml. of water and manufactured intoCTS by a process previously described. After appropriate moistureequilibration, the sheet was cut and manufactured into cigaretteswithout admixture of any out tobacco. These were evaluatedrganoleptically. It was noted that the cigarettes smoked bland, and hadlost much of the undesirable harshness, such as mouth coating and noseand throat irritation, normally found for cigarettes made from untreatedCTS. The smoke from the treated product had a milder, sweeter taste.

Example 2 A mixture composed of 1820 grams of powdered tobacco and stemmaterials was admixed with 1000 ml. of water, placed in two 3-literflasks and treated with steam under pressure under similar conditions tothose noted for Example 1. After cooling, the mixture was mixed with207.5 grams of guar gum, 160 grams of alpha cellulose, 145 ml. ofhumectant glycols, and an additional 500 ml. of water. The resultant wetmix was rolled into a coherent sheet by the previously described processand dried quickly to conditions for cutting and cigarette manufacture.Sample cigarettes prepared with the treated prod uct were evaluatedorganoleptically and were judged to smoke milder with less throat andnose irritation than the regular CTS sample. The smoke though possessingtypical CTS taste, was more fully balanced than normal CTS.

Example 3 A 7.5 pound sample of regular, production wet CTS mix, similarto that described in Example 1, and containing all of the ingredientsrequired for the manufacture of a coherent sheet with the exception thatonly 80-90% of the normal water content was present, was obtaineddirectly from the factory CTS production line. This mixture was placedin a glass battery jar 8 inches in diameter Example 4 A mixture composedof 1820 grams of powdered tobacco and stem materials was admixed with1000 ml. of

water and treated in a container as described in Example 3. Aftercooling, the product was mixed with 207.5 grams of guar gum, 160 gramsof alpha cellulose, 145 ml. of humectant glycols, and an additional 500m1. of water. The resulting wet mix was rolled into a continuouscoherent sheet as previously described Cigarettes manufactured from thissample were judged to have a taste typical of untreated CTS withdecreased nose and throat irritation. This sample was preferred over theuntreated control but not over the sample prepared as in Example 3.

Example 5 A 7.5-pound sample of regular production wet CTS mix, similarto that described in Example 3, and containing all of the ingredientsrequired for the manufacture of a coherent sheet, with the exceptionthat only -90% of the normal water content was present, was obtaineddirectly from the factory CTS production line. This mixture was placedin stainless steel trays to a depth of only 1 inch. The loaded trayswere treated. in an autoclave for 20 minutes at a gauge reading of 16p.s.i. of steam pres sure. It was determined that under these conditionsthe tobacco mass attained a temperature of 225 F. throughout. Aftercooling, the material was rolled to form a coherent sheet as previouslydescribed for the preparation of CT S. Cigarettes manufactured from thistreated product were judged by organoleptic testing to possess a bittertaste with typical CTS character. This sample was rejected as lessdesirable than the regular production CTS.

Example 6 Samples of regular production wet CTS mix containing all ofthe ingredients required for the manufacture of a coherent tobaccosheet, with the exception that only 80- 90% of the normal water contentwas present, were placed in glass battery jars and treated in batches of15 pounds each as described in Example 3. Sufiicient wet CTS mix wastreated in this way over several days to produce about 450 pounds offinished sheet by the usual process. A portion of the sheet preparedfrom the treated CTS mix was blended with strip tobacco and manufacturedinto mm. non-filter cigarettes by standard factory operations. The levelof content of the treated CTS was twice that used for comparablecigarettes prepared with CTS not treated by the method of the presentinvention. A sample of regular production 85 mm. non-filter cigaretteswas prepared using untreated CTS at the normal level (one-half of thatused above). The overall smoking qualities and acceptability for thesetwo samples were compared by an expert smoke flavor panel. The flavorprofile for the cigarette incorporating the treated CTS at twice thenormal level showed a slight broadening of the smoke flavor spectrum andan apparent decrease in mouth and throat irritation factors.

These cigarettes were next presented to a consumer smoking panel forcomparison. The sample cigarettes containing CTS treated by theprocedure of this invention at a level twice that present in thecontrol, production cigarette was preferred by a ratio of 1.6 to 1.0. Ananalysis of the individual smokers comments indicated that the majorityof those who preferred the sample containing treated CTS based theirpreference on both improved taste and lessened irritation.

Samples of the CTS were tested for flexibility and tensile strength andthe results of these tests are set forth below.

TABLE I. PHYSICAL PROPERTIES OF CIS SAMPLES [Flexibility strength,kgmJem Thickness of test Sheet, mm 0.09 0.10 0.11 0. 12 0.13 AverageValues CTS sheet prepared from materials treated as described in Example6:

Preparation 1:

With grain 39.5 36.4 34.9 31.8 35.6 Against grain 16. 3 11. 7 3. 3 14. 511.; Preparation 2:

With grain 36.5 37. 7 34.2 27.8 34. 0 Against grain 0. 6 8. 7 4. 5 3. 4Control sample C'IS sheet prepared from the same mix as used for Example6 but not treated by the process of this invention:

With grain 30. 1 24.4 24.1 25. 5 21.1 25. 0 Against grain 0. 6 0.7 0.70.9 4. 8 1. 5

TABLE II [Tensile strength, kgmJcmfl] Thickness of test sheet, mm 0. 090.10 0. 11 0.12 0.13 Average Values CTS sheet prepared from materialstreated as described in Example 6:

Preparation 1:

With grain 55. 6 52.0 35. 5 49.1 53. 3 Against grain 30. 6 35.4 36.2 39.0 35. 3 Preparation 2:

With grain 51. 7 33. 6 45.9 41.0 42. 3 42. 9 Against grain 49. 3 30.430. 6 34. 3 31.0 36. 3 Control samples of CTS sheet without treatment bythe process of this invention:

With grain 41. 0 37.8 36. 3 37. 2 38.9 38. 2 Against grain 26.4 24.1 22.3 21. 7 21.2 23.1

Example 7 cigarette containing untreated CTS at the same level (twotimes the production level) a great preference was obtained for theproduct containing the treated CTS.

Samples of the treated CTS used for the above preparation were evaluatedby the testing group for physical characteristics. All samples showedexceptionally high flexibility and tensile strengths. This data is setforth below.

TABLE III.PIIYSICAL PROPERTIES OF CTS SAMPLES [Flexibility strength,kgrnjcmfl] Thickness of test sheet, mm 0.09

0.10 0.11 0.13 0.14 Average Values With grain Against grain Preparation4:

With grain Against grain Control sample CTS sheet prepared from the samemix as used for Example 7 but not treated by the process of thisinvention:

With grain 30. Against grain 0.

0. 14 Average Values TABLE IV [Tensile strength, kgmJcmJ} described inExample 7:

Preparation 1:

Thickness of test sheet mmIIIIIIIII- CTS sheet prepared from materialstreated as 0. 14 Average Values TABLE VI [Tensile strength, kgnL/emfi]described in Example 8:

Preparation 1:

Thickness of test sheet, nmi.

CTS sheet prepared from materials treated as With grain.

Against grain Preparation 2:

With grain Against grain. Preparation 3:

With grain....

Against grain Control sample CTS sheet prepared from is same mix as usedfor Example 8, preparations 1 and 2, but not treated by the process ofthis invention:

Control sample CTS sheet prepared from the same mix as used for Example8, preparations 3, but not treated by the process of this invention:

With grain..-

Against grain CTS sheet prepared from materials treated as described inExample 8:

Preparation 4:

With grain Against grain. Control sample CTS sl same mix as used forExample 8, preparation 4, but not treated by the process of thisinvention:

Against grain CTS sheet prepared from materials treated as described inExample 8:

Preparation 5:

oml 43 &2 33

With grain-.

Against grain Preparation 6:

Against grain Preparation 7:

With grain pie 8, preparations Against grain. Control sample CTS sheetsame mix as used for Exam 5 and 6 ,but not treated by the process ofthis invention:

With grain.

Against grain.

Control sample CTS sheet prepared from the same mix as used for Example8, preparation 7, but not treated by the process of this invention:

With grain Against grain.

iength of the CTS sheetproduced samples were compared to similarmeasurements for CTS sheet processed from the same 10.4 Average Valuesinch. The loaded trays were treated in an autoclave for Example 9 20minutes at 16 p.s.1. of steam pressure. Under these 011 Wet CTStreatment conditions the total tobacco mass reached a temperature of 225F. Measurements of relative flex 0 bility and tensile str from thesetreated mix without the treatment of this invention. These data are setforth below:

TABLE VlL-PHYSIOAL PROPERTIES OF CTS SAMPLES [Flexibility strength,kgm./em.

described in Example 9:

Preparation 1 1110):

A 5.5-pound sample of "regular product mix, similar to that described inExample 1, and con- Thickness oi test sheet, mm

CTS sheet prepared from materials treated as taining all of theingredients required for the manufacture 5 of a coherent sheet, with theexception that 65-85% of the normal water content was present, wasobtained directly from the factory CTS production line. This mixture wasplaced in stainless steel trays to a depth of one Against grainPreparation 2 (65% H O):

Against grain Preparation 3 I110);

Against grain Preparations I120):

With grain..

Against grain Preparation 5 E 0):

TABLE VIII [Tensile strength, kgmJemfi] Thickness of test sheet, mm 0.O9 0. 10 0.11 0.12 0.13 0. 14 Average Values CTS sheet prepared frommaterials treated as described in Example 9:

Preparation 1 (65% B With grain 53. 0 52. 6 49. 9 48. 3 47. 1 50. 2Against grain 33. 1 33. 6 24. 2 29. 1 30. 4 30.1 Preparation 2 (65% HzWith grain 46. 1 43. 8 42. 3 42. 6 43. 7 Against grain 26. 0 34. 8 30. 329. 9 30.3 Preparation 3 (75% E20):

With grain 45. 2 52.1 49. 7 50. 9 49. 5 Against grain 34. 7 30. 7 31. 035.8 33. 0 Preparation 4 (80% E 0) With grain 49. 6 46. 7 46. 6 48. 4Against grain 36.1 34. 3 34.2 34. 2 Preparation 5 (85% E) With grain 48.7 51. 7 44.8 48. 1 47. 4 Against grain 38. 8 38. 6 34. 8 34.0 34. 6Control sample CTS sheet prepared from the same mix used for Example 9,but not treated by the process of this invention With grain 39. 7 40. 739. 2 38. 4 35. 1 36. 4 38. 2 Against grain. 26. O 23. 0 20. 3 22. 3 18.9 24. 9 22. 6

Having thus provided a written description of the present invention andprovided specific examples thereof, it should be understood that noundue restrictions or limitations are to be imposed by reason thereofbut that the present invention is defined by the appended claims.

What is claimed is:

1. A process for producing improved coherent tobacco strip havingreduced irritation properties which comprises thoroughly mixing tobaccofines, humectant and Water in a reactor, heating said mixture underpressures of up to about 20 p.s.i.g. for a period of up to about 20minutes at temperatures not exceeding about 225 F. in the ground tobaccoand sheeting the mixture to produce a coherent tobacco strip.

2. A process for producing improved coherent tobacco strip havingreduced irritation properties which comprises thoroughly mixing in anautoclave tobacco fines, humectant and about 65 to 85% of the waternormally employed in producing coherent tobacco strip, heating saidmixture under pressures of up to about 20 p.s.i.g. for a period of up toabout 20 minutes at temperatures not exceeding about 225 F. in theground tobacco and sheeting the mixture to produce a coherent tobaccostrip.

3. A process for improving coherent tobacco strip having reducedirritation characteristics and increased flexibility strength whichcomprises thoroughly mixing tobacco fines, at least one humcctant andguar gum with water in a reactor, heating said mixture under steampressures of up to about 20 p.s.i.g. for a period of up to about 20minutes at temperatures not exceeding about 225 F. in the ground tobaccoand sheeting the mixture to produce a coherent tobacco strip.

4. A process for producing coherent tobacco strip having reducedirritation properties and increased flexibility strength which comprisesthoroughly mixing in an autoclave tobacco fines, at least one humectant,guar gum and about 65-85% of the water normally employed in producingcoherent tobacco strip, heating said mixture under steam pressures of upto about 20 p.s.i.g. for a period of time of up to about 20 minutes attemperatures not exceeding about 225 F. in the ground tobacco andsheeting the mixture to produce a coherent tobacco strip.

5. A process for producing improved coherent tobacco strip havingreduced irritation effects which comprises thoroughly mixing about 45 to60 parts by weight of ground tobacco fines, about 1 to 8 parts by weightof at least one humectant with the balance of said composition beingwater, heating said mixture in a reactor under steam pressures of up toabout 20 p.s.i.g. for a period of time up to about 20 minutes attemperatures not exceeding about 225 F. in the ground tobacco andsheeting the mixture to produce a coherent tobacco strip.

6. A process for producing improved coherent tobacco strip havingreduced irritation effects which comprises thoroughly mixing in anautoclave about 50 to 55 parts by weight of ground tobacco fines, about2 to 5 parts by weight of at least one humectant, and about 29 to 40parts water, heating said mixture under steam pressures of up to about20 p.s.i.g. for a period of time up to about 20 minutes at tempearturesnot exceeding about 225 F. in the ground tobacco and sheeting themixture to produce a coherent tobacco strip.

7. A process for producing improved coherent tobacco strip havingreduced irritation properties and increased flexibility strength whichcomprises thoroughly mixing about to 60 parts by weight of groundtobacco fines, about 1 to 8 parts by weight of at least one humectant,and about 1 to 10 parts by weight of guar gum with the balance of saidcomposition being water, heating said mixture in a reactor under steampressures of up to about 20 p.s.i.g. for a period of time up to about 20minutes at temperatures not exceeding about 225 F. in the ground tobaccoand sheeting the mixture to produce a coherent tobacco strip.

8. A process for producing improved coherent tobacco strip havingreduced irritation properties and increased flexibility strength whichcomprises mixing in an autoclave about to parts by weight of groundtobacco fines, about 2 to 5 parts by weight of at least one humecrant,about 2 to 8 parts by weight of guar gum and about 29 to 40 parts water,heating said mixture under steam pressures of up to about 20' p.s.i.g.for a period of time up to about 20 minutes at temperatures notexceeding about 225 F. in the ground tobacco and sheeting the mixture toproduce a coherent tobacco strip.

9. A process for producing an improved coherent tobacco strip havingreduced irritation properties which comprises thoroughly mixing about 45to parts by weight of ground tobacco fines, about 1 to 8 parts by weightof at least one humectant with the balance of said composition beingwater, heating said mixture in a reactor under steam pressures of about8 to 20 p.s.i.g. for a period of about 10 to 20 minutes at temperaturesin the range of about to 225 F. in the ground tobacco and sheeting themixture to produce a coherent tobacco strip.

10. A process for the preparation of an improved tobacco strip havingreduced irritation properties which comprises thoroughly mixing in anautoclave about 50 to 55 parts by weight of ground tobacco fines, about2 to 5 parts by weight of at least one humectant with about 29 to 40parts water, heating said mixture under steam pressures of about 8 to 20p.s.i.g. for a period of about 10 to 20 minutes at temperatures in therange of about 170 to 225 F. in the ground tobacco and sheeting themixture to produce a coherent tobacco strip.

11. A process for the preparation of an improved tobacco strip havingreduced irritation properties and increased flexibility strength whichcomprises thoroughly mixing about 45 to 60 parts by Weight of groundtobacco fines, about 1 to 8 parts by weight of at least one humectant,about 1 to 10 parts by weight of guar gum with the balance of saidcomposition being water, heating said mixture in a reactor under steampressures of about 8 to 20 p.s.i.g. for a period of about 10 to 20minutes at tempera tures in the range of about 170 to 225 F. in theground tobacco and sheeting the mixture to produce a coherent tobaccostrip.

12. A process for the preparation of an improved coherent tobacco striphaving reduced irritation properties and increased flexibility strengthwhich comprises thoroughly mixing about 50 to about 55 parts by weightof ground tobacco fines, about 2 to about 5 parts by weight of at leastone humectant, about 2 to 8 parts by weight of guar gum with the balanceof said composition being water, heating said mixture in a reactor underpressures of about 8 to 16 p.s.i.g. for a period of about to about 20minutes at temperatures in the range of 170 to 225 F. in the groundtobacco and sheeting the mixture to produce a coherent tobacco strip.

13. A process for the preparation of an improved coherent tobacco striphaving reduced irritation properties and increased flexibility strengthwhich comprises thoroughly mixing about 45 to 60 parts by weight ofground tobacco fines, about 1 to 8 parts by weight of at least onehumectant, about 1 to 10 parts by weight of guar gum with the balance ofsaid composition being water, heating said mixture in a reactor understeam pressures of about 8 to 20 parts p.s.i.g. for a period of about 10to 20 minutes at temperatures in the range of about 170 to 225 F. andsheeting the mixture to produce a coherent tobacco strip, thetemperatures, pressures and time in the upper part of the ranges beingemployed if it is desired to maximize the increase in flexibilitystrength of the CTS and the lower range of temperatures, times andpressures being employed if it is desired to maximize the reduction inirritation properties of the CTS.

1 4. A process for the preparation of an improved coherent tobacco striphaving reduced irritation effects and increased flexibility strengthwhich comprises thoroughly mixing in an autoclave about 50 to 55 partsby weight of ground tobacco fines, about 2 to about 5 parts by Weight ofat least one humectant, about 2 to about 8 parts by weight of guar gumwith the balance of said composition being water, heating said mixtureunder steam pressures of about 8 to about 16 p.s.i.g. for a period of upto about 20 minutes at temperatures in the range of about 170 to 225 F.in the ground tobacco and sheeting the mixture to produce a coherenttobacco strip, temperatures, pressures and times in the upper part ofthe ranges being employed if it is desired to maximize the flexibilitystrength of the CTS while temperatures, times and pressures in the lowerpart of the ranges are employed if it is desired to maxi mize thereduction in irritation properties of the CTS.

15. A process for the preparation of an improved coherent tobacco striphaving reduced irritation characteristics and improved flexibilitystrength which comprises thoroughly mixing in an autoclave about toparts by weight of ground tobacco fines, about 2 to about 5 parts byweight of at least one humectant, about 2 to about 8 parts by weight ofguar gum with about 29 to 40 parts water, heating said mixture understeam pressures of about 8 to 16 p.s.i.g. for a period of about 10 toabout 20 minutes at temperatures in the range of about to 225 F. in theground tobacco and sheeting the mixture to produce a coherent tobaccostrip, the higher temperatures, pressures and time being employed if itis desired to maximize the flexibility strength of the CTS While thelower times, temperatures and pressure ranges are employed if it isdesired to maximize the reduced irritability characteristics of the CTS.

16. An improved coherent tobacco strip produced by the process of claim9 and having reduced irritation properties when incorporated in asmoking tobacco article.

17. An improved coherent tobacco strip produced by the process of claim11 and having increased flexibility strength and having reducedirritation characteristics when incorporated in a smoking tobaccoarticle.

18. A smoking tobacco article having improved smoking characteristicsand reduced irritation characteristics comprising a mixture of naturaltobacco and coherent tobacco strip prepared by the process of claim 13.

References Cited UNITED STATES PATENTS 2,613,672 10/1952 Sartoretto etal. 131-140 X 2,708,175 5/1955 Samfield et al. 131140 3,020,179 2/1962Hess 131140 SAMUEL KOREN, Primary Examiner.

MELVIN D. REIN, Examiner.

1. A PROCESS FOR PRODUCING IMPROVED COHERENT TOBACCO STRIP HAVINGREDUCED IRRITATION PROPERTIES WHICH COMPRISES THROUGH MIXING TOBACCOFINES, HUMECTANT AND WATER IN A REACTOR, HEATING SAID MIXTURE UNDERPRESSURES OF UP TO ABOUT 20 P.S.I.G. FOR A PERIOD OF UP TO 20 MINUTES ATTEMPERATURES NOT EXCEEDING ABOUT 225*F. IN THE GROUND TOBACCO ANDSHEETING THE MIXTURE TO PRODUCE A COHERENT TOBACCO STRIP.